US4776970A - Lubricant for use in paper coating and method for producing the same - Google Patents

Lubricant for use in paper coating and method for producing the same Download PDF

Info

Publication number
US4776970A
US4776970A US06/932,252 US93225286A US4776970A US 4776970 A US4776970 A US 4776970A US 93225286 A US93225286 A US 93225286A US 4776970 A US4776970 A US 4776970A
Authority
US
United States
Prior art keywords
lubricant
acid
carbon atoms
paper
parts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/932,252
Inventor
Yoshihiro Hayashi
Takeshi Okubo
Kazuhiro Takeshita
Akinori Higuchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
San Nopco Ltd
Original Assignee
San Nopco Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP60262132A external-priority patent/JPS62104829A/en
Priority claimed from JP60262131A external-priority patent/JPH0660477B2/en
Application filed by San Nopco Ltd filed Critical San Nopco Ltd
Assigned to SAN NOPCO LIMITED reassignment SAN NOPCO LIMITED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HAYASHI, YOSHIHIRO, HIGUCHI, AKINORI, OKUBO, TAKESHI, TAKESHITA, KAZUHIRO
Application granted granted Critical
Publication of US4776970A publication Critical patent/US4776970A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/36Coatings with pigments
    • D21H19/44Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
    • D21H19/46Non-macromolecular organic compounds
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B24/00Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • C04B24/04Carboxylic acids; Salts, anhydrides or esters thereof
    • C04B24/045Esters, e.g. lactones
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/03Non-macromolecular organic compounds
    • D21H17/05Non-macromolecular organic compounds containing elements other than carbon and hydrogen only
    • D21H17/14Carboxylic acids; Derivatives thereof
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H19/00Coated paper; Coating material
    • D21H19/36Coatings with pigments
    • D21H19/44Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
    • D21H19/62Macromolecular organic compounds or oligomers thereof obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2103/00Function or property of ingredients for mortars, concrete or artificial stone
    • C04B2103/0068Ingredients with a function or property not provided for elsewhere in C04B2103/00
    • C04B2103/0075Anti-dusting agents
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H21/00Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
    • D21H21/14Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
    • D21H21/16Sizing or water-repelling agents
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/31504Composite [nonstructural laminate]
    • Y10T428/31971Of carbohydrate
    • Y10T428/31993Of paper

Definitions

  • the present invention relates to a lubricant for use in paper coating. More particularly, it relates to a lubricant for use in paper coating compositions composed mainly of pigments and binders.
  • lubricants for use in paper coating there have been used metal salts of higher fatty acids, higher fatty acid amides, wax emulsions, polyethylene glycol, polyethylene glycol esters, liquid hydrocarbon oil emulsions, polyethylene dispersions and aliphatic sulfated oils.
  • metal salts of higher fatty acids, higher fatty acid amides, wax emulsions, polyethylene glycol, polyethylene glycol esters, liquid hydrocarbon oil emulsions, polyethylene dispersions and aliphatic sulfated oils have a defect that, because of their poor releasing effect and antidusting effect during calendering of offset paper, gravure paper, etc., stains are produced on the surface of calender rolls.
  • these lubricants have a defect that, because of their entire shortage of the anti-dusting effect during supercalendering, marked dusting is generated on the supercalenders to often force a person to stop calendering and clean the surface of calender rolls.
  • Increasing the amount of lubricant added can decrease the generation of dusting to some degree but it causes a reduction in the friction coefficient of coated paper to impart to the paper too much slip which hinders rewinding of the coated paper, sheet feeding to a sheet-fed press, etc.
  • these lubricants have a defect that they have little effect to improve the print gloss of coated paper.
  • higher fatty acid esters such as higher fatty acid sucrose esters [Japanese patent Kokai No. 55,707/1977. ] and aqueous emulsions of dimers of higher fatty acids (ibid., No. 65,074/1981) can be used as antiblocking agents or antidusting agents. All of these higher fatty acid esters, however, are insufficient in any of the releasing effect, antidusting effect and print gloss improving effect like the foregoing lubricants, it being impossible to solve the defects of the conventional lubricants. Further, these higher fatty acid esters have a defect of increasing the missing dots rate in gravure printing.
  • the present inventors extensively studied to develop a lubricant which is superior in the releasing effect and antidusting effect during calendering as compared with the conventional lubricants, and yet exhibits not only these effects but also the print gloss improving effect at lower dosage levels than in the conventional lubricants. As a result, the present inventors attained to the present invention.
  • the present invention provides a lubricant for paper coating which comprises the aqueous dispersion of an ester compound represented by the general formula (I), ##STR2## wherein R represents an alkyl or alkenyl group having 3 or more carbon atoms or an alkyl or alkenyl group having a hydroxyl group, and R' represents an alkyl or alkenyl group having 4 or more carbon atoms, provided that the total number of carbon atoms of R and R' is 15 or more.
  • R represents an alkyl or alkenyl group having 3 or more carbon atoms or an alkyl or alkenyl group having a hydroxyl group
  • R' represents an alkyl or alkenyl group having 4 or more carbon atoms, provided that the total number of carbon atoms of R and R' is 15 or more.
  • the number of carbon atoms of R representing an alkyl or alkenyl group or the same group having a hydroxyl group is generally 3 or more, preferably from 7 to 21, more preferably from 11 to 21.
  • the number of carbon atoms of R' representing an alkyl or alkenyl group is generally 4 or more, preferably from 8 to 22, more preferably from 12 to 22.
  • the total number of carbon atoms of R and R' is generally 15 or more, preferably from 19 to 43, more preferably from 23 to 43.
  • R is the residue of a saturated or unsaturated carboxylic acids having 3 or more carbon atoms.
  • carboxylic acids saturated fatty acids such as butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, etc.; unsaturated fatty acids such as butenoic acid, pentenoic acid, hexenoic acid, heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid
  • fatty acids preferred ones are fatty acids having from 8 to 22 carbon atoms, and more preferred ones are straight-chain saturated fatty acids having from 12 to 22 carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid.
  • R may be the residue of carboxylic acid anhydrides or carboxylic acid halides, and for example there may be mentioned saturated or unsaturated fatty acid anhydrides such as caprylic acid anhydride, stearic acid anhydride, oleic acid anhydride, etc.; and saturated or unsaturated fatty acid halides such as caprylic acid chloride, palmitic acid bromide, stearic acid chloride, oleic acid chloride, etc.
  • carboxylic acids may be used alone or in mixture of two or more of them.
  • carboxylic acids having an aromatic group such as benzoic acid, ⁇ -phenylcapric acid, etc., or halogenated fatty acids such as chlorinated stearic acid, etc. may be used together.
  • R' is the residue of saturated or unsaturated alcohols having 4 or more carbon atoms.
  • Saturated aliphatic alcohols such as butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, eicosyl alcohol, behenyl alcohol, 2-undecyltetradecyl alcohol, etc.; unsaturated alcohols such as dodecenol, fiseteryl alcohol, oleyl alcohol, gadoleyl alcohol, 11-docosenol, etc.; alcohols having a carbon ring such as cyclohexanol, etc.; and structurally isomeric alcohols of the above saturated
  • aliphatic alcohols preferred ones are aliphatic alcohols having from 8 to 22 carbon atoms, and more preferred ones are saturated aliphatic alcohols having from 12 to 22 carbon atoms such as lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, etc.
  • the emulsifier or dispersant used for emulsification or dispersion of said ester compounds comprises as integral ingredients either at least one nonionic surfactant selected from the group consisting of polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers and polyoxyethylene alkyl esters and at least one anionic surfactant selected from the group consisting of sulfonate-type and sulfate-type anionic surfactants, or the salt of copolymers of an ⁇ , ⁇ -unsaturated dibasic acid or its monoester with styrene. Containing these ingredients is a requirement for obtaining stable emulsions or dispersions having a high concentration and low viscosity
  • Polyoxyethylene alkylphenyl ether includes addition polymers of an alkyl group-substituted phenol with ethylene oxide.
  • the number of carbon atoms of said alkyl group is generally from 6 to 12, preferably from 7 to 10, more preferably from 8 to 9, and the number of moles of ethylene oxide used in the addition polymerization is generally from 4 to 70, preferably from 4 to 50, more preferably from 5 to 25.
  • Polyoxyethylene alkyl ether includes addition polymers of a higher alcohol with ethylene oxide.
  • the number of carbon atoms of said higher alcohol is generally from 8 to 20, preferably from 12 to 20, more preferably from 16 to 18, and the number of moles of ethylene oxide used in the addition polymerization is generally from 5 to 70, preferably from 13 to 50, more preferably from 22 to 45.
  • Polyoxyethylene alkyl ester includes mono- or diesters of a higher fatty acid with polyethylene glycol.
  • the number of carbon atoms of said higher fatty acid is generally from 8 to 20, preferably from 12 to 20, more preferably from 16 to 18, and polyethylene glycol comprises generally from 5 to 70 moles, preferably from 13 to 50 moles, more preferably from 22 to 45 moles of ethylene oxide.
  • a more preferred polyoxyethylene alkyl ester is the monoester which is low in thickening effect.
  • the sulfonate-type anionic surfactant includes for example alkylbenzene sulfonates such as tetrapropylenebenzenesulfonates, straight-chain dodecylbenzenesulfonates, eicosylbenzenesulfonates, etc.; ⁇ -olefinsulfonates such as 1-hexadecenesulfonates, etc.; N-methyl-N-oleyltaurine; dialkyl sulfosuccinates such as di-2-ethylhexyl sulfosuccinates, etc.; alkylsulfonates such as tetradecylsulfonates, hexadecylsulfonates, petroleumsulfonates, etc.; ⁇ -sulfofatty acid salts such as ⁇ -sulfopalmitates, etc.; ester containing sulfonates such as ethyl ⁇ -
  • the sulfate-type anionic surfactant includes for example alkyl sulfates such as stearyl sulfates, etc.; sulfated oils
  • sulfated castor oil such as sulfated castor oil, etc.; polyoxyethylene alkyl ether sulfates, polyoxyethylene styrenated phenyl ether sulfates.
  • the sulfonates and sulfates as used herein refer to the ammonium, sodium, potassium, calcium, magnesium and amines (e.g. diethanolamine) salts of a sulfonic acid group or sulfuric acid group.
  • anionic surfactants preferred ones are alkylbenzenesulfonates such as straight-chain dodecylbenzenesulfonates, etc.; alkylsulfonates such as tetradecylsulfonates, hexadecylsulfonates, petroleumsulfonates, etc.; naphthalenesulfonate/formaldehyde condensates having a condensation degree of from 2 to 10; and stearylsulfates.
  • Preferred salts are the ammonium salt, sodium salt and potassium salt.
  • the salts of the copolymers of an ⁇ , ⁇ -unsaturated dibasic acid or its monoester with styrene include for example the salts of copolymers of styrene with the following acids or their monoesters: maleic acid, fumaric acid, monomethyl maleate, monoisopropyl maleate, monobutyl maleate, monoester of maleic acid with ethylene glycol monobutyl ether, etc.
  • Preferred salts include generally alkali metal salts and ammonium salts.
  • the emulsifier or dispersant When the emulsifier or dispersant is said nonionic surfactant, its amount used is generally from 3 to 40 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts by weight of said ester compound (I).
  • the emulsifier or dispersant When the emulsifier or dispersant is said anionic surfactant, its amount used is generally from 0.1 to 10 parts by weight, preferably from 0.2 to 5 parts by weight, more preferably from 0.3 to 2 parts by weight based on 100 parts by weight of said ester compound (I).
  • the emulsifier or dispersant is the salts of copolymers of an ⁇ , ⁇ -unsaturated dibasic acid or its monoester with styrene
  • its amount used is generally from 2 to 30 parts by weight, preferably from 3 to 20 parts by weight based on 100 parts by weight of said ester compound (I).
  • the aqueous dispersion of the ester compound (I) can be obtained as follows: The compound (I) is melted at a temperature of from 60° to 150° C. and poured into water of from 60° to 100° C. containing a required amount of dissolved emulsifier or dispersant, or a required amount of the emulsifier or dispersant is previously dissolved in the melted ester compound (I) of from 60° to 150° C. and poured into water of from 60° to 100° C.; and the resulting mixture is emulsified or dispersed at a temperature of from 60° to 100° C.
  • the ester compound (I) can be synthesized by the conventional methods. For example, a fatty acid or its acid halide and a monohydric aliphatic alcohol in a former to latter molar ratio of, generally, 1 to 1, or a fatty acid anhydride and a monohydric aliphatic alcohol in a former to latter molar ratio of, generally, 1 to 2 are subjected to dehydration or dehydrohalogenation at a temperature of from 70° to 200° C.
  • catalysts such as hydrogen chloride, sulfuric acid, p-toluenesulfonic acid, boron trifluoride etherate, etc. may be used together.
  • Dehydration or dehydrohalogenation may be carried out under reduced pressure, or dehydration may be carried out azeotropically using a solvent such as toluene, xylene, etc.
  • lubricants for paper coating of the present invention may be mixed, in advance or in situ, with antioxidants, ultraviolet absorbers, water insolubilizers, antiseptic/anti-mould agents, insecticidal/fungicidal agents, dispersing agents, defoaming agents, deodorizing agents, perfumes, extenders, dyes, pigments, or other lubricants (e.g. calcium stearate, zinc stearate, potassium oleate, paraffin wax, polyethylene wax).
  • antioxidants e.g. calcium stearate, zinc stearate, potassium oleate, paraffin wax, polyethylene wax.
  • the lubricants are added to paper coating colors composed mainly of pigments and binders.
  • the pigments include inorganic pigments such as clay, calcium carbonate, titanium dioxide, satin white, barium sulfate, talc, zinc oxide, etc., organic pigments such as plastic pigments (polystyrene described in Japanese patent Publication No. 6524/1971) and combinations thereof.
  • the binders include natural binders, synthetic binders and mixtures thereof.
  • the natural binders include starch, modified starch, soybean protein, casein, etc.
  • the synthetic binders include styrene/butadiene latices; acrylic resin emulsions, particularly aqueous suspensions of polymers containing a small amount of a copolymerized ethylenically unsaturated carboxylic acid; butadiene/acrylonitrile copolymers, vinyl acetate/acrylate copolymers, butadiene/methyl methacrylate copolymers, vinyl chloride/vinylidene chloride copolymers, homopolymers comprising butadiene, methyl methacrylate, vinyl acetate, chloroprene, vinyl chloride and butyl methacrylate; and latices of polymeric materials which are at least partially soluble in aqueous media such as polyvinyl alcohol.
  • the amount calculated as solid of the lubricants for paper coating of the present invention is generally from 0.1 to 20 parts by weight, preferably from 0.2 to 10 parts by weight, more preferably from 0.3 to 5 parts by weight based on 100 parts by weight of the pigments.
  • any of the releasing effect, antidusting effect and print gloss improving effect is insufficient, and when it is larger than 20 parts by weight, the coated paper becomes too slippery, either of the both cases being not preferred.
  • the paper coating colors obtained with the lubricants for paper coating of the present invention are generally used in the form of aqueous dispersions.
  • other additives such as dispersing agents (e.g. sodium pyrophosphate, sodium hexametaphosphate, sodium polyacrylate), defoaming agents (e.g. paraffin, phosphoric acid esters, polyglycol, silicone compounds), leveling agents (e.g. urea, dicyandiamide), water retention agents, flow modifiers (e.g. carboxymethyl cellulose, sodium alginate, hydroxyethyl cellulose), water insolubilizers (e.g. urea resins, melamine resins, glyoxal), antiseptic agents (e.g. formalin), fluorescent dyes, etc.
  • dispersing agents e.g. sodium pyrophosphate, sodium hexametaphosphate, sodium polyacrylate
  • defoaming agents e.g. paraffin, phosphoric acid esters,
  • the paper coating colors of the present invention can be applied to base papers, for example, by means of air knife coaters, trailing blade coaters, inverted coaters, roll coaters, applicators, etc. After coating, the coated paper is dried and if necessary, finished by calendering or supercalendering.
  • the coating temperature is generally from 10° to 60° C.
  • the drying temperature is generally from 90° to 130° C.
  • the calendering temperature and supercalendering temperature are from 40° to 100° C.
  • the lubricants for paper coating of the present invention are very superior in the releasing effect and antidusting effect during calendering, and yet these effects are far superior to those of the conventional lubricants such as calcium stearate, etc. even at as low a dosage as from half to one-third of that of the conventional lubricants. Further, such a great reduction in the dosage made it possible to eliminate various adverse effects which cannot be avoided when the conventional lubricants are used at high dosage levels for the purpose of antidusting. Such adverse effects include efficiency reduction of paper rewinding and sheet feeding to a sheet-fed press owing to too much slip of paper, reduction in printability such as ink receptivity and wet strength of coated paper, reduction in glueability and blister pack property of coated white board, etc.
  • the lubricants of the present invention have an effect to improve the print gloss of coated paper which has never been obtained with the conventional lubricants. Further, the lubricants, because of their antidusting effect, have also effects of improving the smoothness of coated paper, reducing missing dots in gravure printing and improving sheet gloss.
  • the lubricants for paper coating of the present invention can also be used as a sizing agent.
  • the dosage can be varied, but it is generally from 0.01 to 5 wt. %, preferably from 0.05 to 2 wt. %, more preferably from 0.1 to 1 wt. %, as converted to solid basis, based on pulp.
  • Paper which is sizable with the present lubricants is not particularly limited, but covers a wide range of base papers as well as papers made in a wide pH range independently of treatment with paper strength resins.
  • the lubricants of the present invention are used as a sizing agent, it suffices to add the present sizing agent and a fixing agent to an aqueous dispersion containing beaten pulp and a filler such as clay, calcium carbonate, etc. and after mixing, to make paper from the dispersion.
  • the lubricants of the present invention can also be used as a water insolubilizer for cement, gypsum board, etc.
  • lubricant B an emulsion or dispersion having a concentration of 50% and a viscosity of 150 cps was obtained and designated as "lubricant B".
  • a white emulsion or dispersion having a concentration of 50% and a viscosity of 120 cps was obtained and designated as "lubricant C".
  • oleyl oleate 60 g of an addition polymer of lauryl alcohol with 14 moles of ethylene oxide, 25 g of an addition polymer of stearyl alcohol with 23 moles of ethylene oxide, 40 g of a monoester of stearic acid with polyethylene glycol comprising 45 moles of ethylene oxide, 25 g of a monoester of myristic acid with polyethylene glycol comprising 23 moles of ethylene oxide, 10 g of sodium petroleumsulfonate and 0.15 g of potassium hydroxide.
  • lubricant D a pale yellowish white emulsion or dispersion having a concentration of 50% and a viscosity of 60 cps (at 25° C.) was obtained and designated as "lubricant D".
  • Lubricants E to J were obtained in the same condition as in the preparation of the lubricant C. Every lubricant has a concentration of 50%.
  • a white emulsion or dispersion of lauryl stearate having a viscosity of 105 cps is lubricant E.
  • a white emulsion or dispersion of lauryl 12-hydroxystearate having a viscosity of 230 cps is lubricant F.
  • a white emulsion or dispersion of 2-ethylhexyl stearate having a viscosity of 90 cps is lubricant G.
  • a white emulsion or dispersion of butyl stearate having a viscosity of 80 cps is lubricant H.
  • a white emulsion or dispersion of 2-ethylhexyl laurate having a viscosity of 85 cps is lubricant 1.
  • a white emulsion or dispersion of palmityl butyrate having a viscosity of 80 cps is lubricant J.
  • Lubricants K to M were obtained in the same condition as in the preparation of the lubricant C. Every lubricant has a concentration of 50%.
  • An emulsion or dispersion of methyl stearate having a viscosity of 210 cps is lubricant K.
  • An emulsion or dispersion of lauryl acetate having a viscosity of 130 cps is lubricant L.
  • An emulsion or dispersion of butyl caprylate having a viscosity of 75 cps is lubricant M.
  • lubricant N To the same emulsifying machine or disperser as used in the preparation of the lubricant A were added 1130 g of water, 120 g of a addition polymer of nonylphenol with 9.5 moles of ethylene oxide and 10 g of a sodium naphthalenesulfonate/formaldehyde fondensate of an average condensation degree of 3, and the resulting mixture was heated to 70° C. to turn it into uniform solution. After adding 1000 g of ethylene glycol distearate previously heated to 120° C. to the solution with stirring, the mixed solution was emulsified at a high pressure of 300 kg/cm 2 and then immediately cooled to 25° C. Thus, a pale yellowish white emulsion or dispersion having a concentration of 50% and a viscosity of 200 cps was obtained and designated as "lubricant N".
  • Lubricant O A commercially available 50% calcium stearate dispersion was designated as "lubricant O".
  • An emulsion or dispersion of lauryl stearate was prepared in the same manner as in the preparation of the lubricant E except that anionic surfactants, i.e. a sodium napthalenesulfonate/formaldehyde condensate of a condensation degree of 3 and sodium dodecylbenzenesulfonate were not added.
  • anionic surfactants i.e. a sodium napthalenesulfonate/formaldehyde condensate of a condensation degree of 3 and sodium dodecylbenzenesulfonate were not added.
  • the emulsion obtained had an abnormally high viscosity of 15000 cps at a concentration of 50%, and solidified in only one day, so that it could not be put to practical use.
  • Coating colors were prepared using the lubricants A to J and P of the present invention and for comparison, coating colors containing the lubricants K to 0 and no lubricant (blank) were prepared.
  • Coated papers for test were prepared by applying these coating colors and evaluated for the antidusting property during supercalendering and physical properties as coated paper. The results are shown in Tables 1 and 2.
  • the antidusting property was evaluated on both gravure paper prepared with a coating color for gravure printing and offset paper prepared with a coating color for offset printing.
  • the physical properties as coated paper were evaluated on the offset paper.
  • the coating color for gravure printing is a dispersion for paper coating having a solid content of 62% and a pH of 9.0 and comprising 45 parts of No.
  • the coating color for offset printing is a dispersion for paper coating having a solid content of 62% and a pH of 9.0 and comprising 70 parts of No. 1 pre-dispersed clay (the same as above), 15 parts of precipitated calcium carbonate (Tamapal TP-222H; a product of Okutama Kogyo Co.), 15 parts of ground calcium carbonate (Escaron #1500; a product of Sankyo Seifun Kako Co.), 0.2 part of sodium polyacrylate type dispersing agent (the same as above), 5 parts of oxidized starch (MS-3800; a product of Nippon Shokuhin Kako Co.), 12 parts of carboxyl-modified styrene/butadiene copolymeric latex (JSR 0692; a product of Nippon Synthetic Rubber Co.) and 0 to 1 part of the lubricant.
  • No. 1 pre-dispersed clay the same as above
  • 15 parts of precipitated calcium carbonate Tamapal TP-222
  • These coating colors were coated by means of a helicoater onto wood containing paper of a basis weight of 65 g/m 2 for gravure paper and onto wood free paper of the same basis weight for offset paper.
  • the amount of the coating color applied was 12 g/m 2 for gravure paper and 16 g/m 2 for offset paper.
  • the antidusting property was evaluated as follows: The coated paper obtained was passed through a supercalender at a temperature of 70° C. and at a nip pressure of 150 kg/cm, and the state of generation of dusting on the surface of the chilled roll was evaluated with naked eyes and expressed by the 10-point evaluation method. In this evaluation method, 10 is the best and 1 is the poorest.
  • coated paper for measuring the physical properties as coated paper was tested after supercalendering at a temperature of 50° C. and at a nip pressure of 80 kg/cm.
  • the lubricants for paper coating of the present invention exhibit at a low dosage level excellent antidusting effect as well as excellent effect to improve sheet gloss, particularly print gloss.

Abstract

A lubricant for paper coating compositions. The lubricant is an aqueous dispersion of an ester compound of the formula (I): ##STR1## wherein R is an alkyl or alkenyl group having 3 or more carbon atoms or an alkyl or alkenyl group having a hydroxyl group, and R' is an alkyl or alkenyl group having 4 or more carbon atoms, provided that the total number of carbon atoms of R and R' is 15 or more. The lubricant is made by emulsifying or dispersing the ester compound with a high-speed agitation emulsifying device or piston-type high pressure emulsifying device in the presence of water and nonionic and anionic surfactants or the salt of a copolymer of an α,β-unsaturated dibasic acid or its monoester with styrene.

Description

The present invention relates to a lubricant for use in paper coating. More particularly, it relates to a lubricant for use in paper coating compositions composed mainly of pigments and binders.
Hitherto, for lubricants for use in paper coating, there have been used metal salts of higher fatty acids, higher fatty acid amides, wax emulsions, polyethylene glycol, polyethylene glycol esters, liquid hydrocarbon oil emulsions, polyethylene dispersions and aliphatic sulfated oils. These lubricants, however, have a defect that, because of their poor releasing effect and antidusting effect during calendering of offset paper, gravure paper, etc., stains are produced on the surface of calender rolls. Particularly, in producing coated paper with a low adhesive strength binder or coated paper of a low binder level, for example gravure paper, etc., these lubricants have a defect that, because of their entire shortage of the anti-dusting effect during supercalendering, marked dusting is generated on the supercalenders to often force a person to stop calendering and clean the surface of calender rolls. Increasing the amount of lubricant added can decrease the generation of dusting to some degree but it causes a reduction in the friction coefficient of coated paper to impart to the paper too much slip which hinders rewinding of the coated paper, sheet feeding to a sheet-fed press, etc. There is a limitation, therefore, to increasing the amount of lubricant. Also, these lubricants have a defect that they have little effect to improve the print gloss of coated paper.
Recently, it is reported that higher fatty acid esters such as higher fatty acid sucrose esters [Japanese patent Kokai No. 55,707/1977. ] and aqueous emulsions of dimers of higher fatty acids (ibid., No. 65,074/1981) can be used as antiblocking agents or antidusting agents. All of these higher fatty acid esters, however, are insufficient in any of the releasing effect, antidusting effect and print gloss improving effect like the foregoing lubricants, it being impossible to solve the defects of the conventional lubricants. Further, these higher fatty acid esters have a defect of increasing the missing dots rate in gravure printing.
The present inventors extensively studied to develop a lubricant which is superior in the releasing effect and antidusting effect during calendering as compared with the conventional lubricants, and yet exhibits not only these effects but also the print gloss improving effect at lower dosage levels than in the conventional lubricants. As a result, the present inventors attained to the present invention.
The present invention provides a lubricant for paper coating which comprises the aqueous dispersion of an ester compound represented by the general formula (I), ##STR2## wherein R represents an alkyl or alkenyl group having 3 or more carbon atoms or an alkyl or alkenyl group having a hydroxyl group, and R' represents an alkyl or alkenyl group having 4 or more carbon atoms, provided that the total number of carbon atoms of R and R' is 15 or more.
In the general formula (I), the number of carbon atoms of R representing an alkyl or alkenyl group or the same group having a hydroxyl group is generally 3 or more, preferably from 7 to 21, more preferably from 11 to 21. Similarly, the number of carbon atoms of R' representing an alkyl or alkenyl group is generally 4 or more, preferably from 8 to 22, more preferably from 12 to 22. The total number of carbon atoms of R and R' is generally 15 or more, preferably from 19 to 43, more preferably from 23 to 43. When the number of carbon atoms of R is less than 3 or that of R' is less than 4 or the total number of carbon atoms of R and R' is less than 15, the lubricating effect is so insufficient that satisfactory releasing effect and antidusting effect cannot be obtained.
Generally, R is the residue of a saturated or unsaturated carboxylic acids having 3 or more carbon atoms. For example, there may be mentioned the following carboxylic acids: saturated fatty acids such as butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, etc.; unsaturated fatty acids such as butenoic acid, pentenoic acid, hexenoic acid, heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, octadecenoic acid, gadoleic acid, erucic acid, linoleic acid, linolenic acid, stearolic acid, etc.; saturated or unsaturated fatty acids having a carbon ring such as α-cyclohexyldecanoic acid, hydnocarpic acid, etc., fatty acids having a hydroxyl group such as 12-hydroxystearic acid, ricinoleic acid, etc.; and structurally isomeric fatty acids of the above saturated or unsaturated fatty acids such as 2-ethylcaproic acid isostearic acid, oleic acid, elaidic acid, etc.
Among these fatty acids, preferred ones are fatty acids having from 8 to 22 carbon atoms, and more preferred ones are straight-chain saturated fatty acids having from 12 to 22 carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid. Also, R may be the residue of carboxylic acid anhydrides or carboxylic acid halides, and for example there may be mentioned saturated or unsaturated fatty acid anhydrides such as caprylic acid anhydride, stearic acid anhydride, oleic acid anhydride, etc.; and saturated or unsaturated fatty acid halides such as caprylic acid chloride, palmitic acid bromide, stearic acid chloride, oleic acid chloride, etc.
These carboxylic acids, carboxylic acid anhydrides and carboxylic acid halides may be used alone or in mixture of two or more of them.
In addition to the foregoing carboxylic acids, carboxylic acids having an aromatic group such as benzoic acid, ω-phenylcapric acid, etc., or halogenated fatty acids such as chlorinated stearic acid, etc. may be used together.
Generally, R' is the residue of saturated or unsaturated alcohols having 4 or more carbon atoms. For example, there may be mentioned the following alcohols: Saturated aliphatic alcohols such as butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, eicosyl alcohol, behenyl alcohol, 2-undecyltetradecyl alcohol, etc.; unsaturated alcohols such as dodecenol, fiseteryl alcohol, oleyl alcohol, gadoleyl alcohol, 11-docosenol, etc.; alcohols having a carbon ring such as cyclohexanol, etc.; and structurally isomeric alcohols of the above saturated or unsaturated aliphatic alcohols such as 2-ethylhexyl alcohol, isotridecyl alcohol, sec-tridecyl alcohol, isostearyl alcohol, 2-octadecenyl alcohol, etc.
Among these aliphatic alcohols, preferred ones are aliphatic alcohols having from 8 to 22 carbon atoms, and more preferred ones are saturated aliphatic alcohols having from 12 to 22 carbon atoms such as lauryl alcohol, isotridecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, etc.
The emulsifier or dispersant used for emulsification or dispersion of said ester compounds comprises as integral ingredients either at least one nonionic surfactant selected from the group consisting of polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl ethers and polyoxyethylene alkyl esters and at least one anionic surfactant selected from the group consisting of sulfonate-type and sulfate-type anionic surfactants, or the salt of copolymers of an α, β-unsaturated dibasic acid or its monoester with styrene. Containing these ingredients is a requirement for obtaining stable emulsions or dispersions having a high concentration and low viscosity
Polyoxyethylene alkylphenyl ether includes addition polymers of an alkyl group-substituted phenol with ethylene oxide. The number of carbon atoms of said alkyl group is generally from 6 to 12, preferably from 7 to 10, more preferably from 8 to 9, and the number of moles of ethylene oxide used in the addition polymerization is generally from 4 to 70, preferably from 4 to 50, more preferably from 5 to 25.
Polyoxyethylene alkyl ether includes addition polymers of a higher alcohol with ethylene oxide. The number of carbon atoms of said higher alcohol is generally from 8 to 20, preferably from 12 to 20, more preferably from 16 to 18, and the number of moles of ethylene oxide used in the addition polymerization is generally from 5 to 70, preferably from 13 to 50, more preferably from 22 to 45.
Polyoxyethylene alkyl ester includes mono- or diesters of a higher fatty acid with polyethylene glycol. The number of carbon atoms of said higher fatty acid is generally from 8 to 20, preferably from 12 to 20, more preferably from 16 to 18, and polyethylene glycol comprises generally from 5 to 70 moles, preferably from 13 to 50 moles, more preferably from 22 to 45 moles of ethylene oxide. A more preferred polyoxyethylene alkyl ester is the monoester which is low in thickening effect.
The sulfonate-type anionic surfactant includes for example alkylbenzene sulfonates such as tetrapropylenebenzenesulfonates, straight-chain dodecylbenzenesulfonates, eicosylbenzenesulfonates, etc.; α-olefinsulfonates such as 1-hexadecenesulfonates, etc.; N-methyl-N-oleyltaurine; dialkyl sulfosuccinates such as di-2-ethylhexyl sulfosuccinates, etc.; alkylsulfonates such as tetradecylsulfonates, hexadecylsulfonates, petroleumsulfonates, etc.; α-sulfofatty acid salts such as α-sulfopalmitates, etc.; ester containing sulfonates such as ethyl α-sulfolaurate, dioctyl sulfosuccinates, etc.; polyoxyethylene styrenated phenyl ether sulfonates; naphthalenesulfonate/formaldehyde condensates having a condensation degree of from 2 to 12; etc.
The sulfate-type anionic surfactant includes for example alkyl sulfates such as stearyl sulfates, etc.; sulfated oils
such as sulfated castor oil, etc.; polyoxyethylene alkyl ether sulfates, polyoxyethylene styrenated phenyl ether sulfates.
The sulfonates and sulfates as used herein refer to the ammonium, sodium, potassium, calcium, magnesium and amines (e.g. diethanolamine) salts of a sulfonic acid group or sulfuric acid group. Among these anionic surfactants, preferred ones are alkylbenzenesulfonates such as straight-chain dodecylbenzenesulfonates, etc.; alkylsulfonates such as tetradecylsulfonates, hexadecylsulfonates, petroleumsulfonates, etc.; naphthalenesulfonate/formaldehyde condensates having a condensation degree of from 2 to 10; and stearylsulfates. Preferred salts are the ammonium salt, sodium salt and potassium salt.
The salts of the copolymers of an α, β-unsaturated dibasic acid or its monoester with styrene include for example the salts of copolymers of styrene with the following acids or their monoesters: maleic acid, fumaric acid, monomethyl maleate, monoisopropyl maleate, monobutyl maleate, monoester of maleic acid with ethylene glycol monobutyl ether, etc. Preferred salts include generally alkali metal salts and ammonium salts.
When the emulsifier or dispersant is said nonionic surfactant, its amount used is generally from 3 to 40 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts by weight of said ester compound (I). When the emulsifier or dispersant is said anionic surfactant, its amount used is generally from 0.1 to 10 parts by weight, preferably from 0.2 to 5 parts by weight, more preferably from 0.3 to 2 parts by weight based on 100 parts by weight of said ester compound (I). Further, when the emulsifier or dispersant is the salts of copolymers of an α, β-unsaturated dibasic acid or its monoester with styrene, its amount used is generally from 2 to 30 parts by weight, preferably from 3 to 20 parts by weight based on 100 parts by weight of said ester compound (I).
The aqueous dispersion of the ester compound (I) can be obtained as follows: The compound (I) is melted at a temperature of from 60° to 150° C. and poured into water of from 60° to 100° C. containing a required amount of dissolved emulsifier or dispersant, or a required amount of the emulsifier or dispersant is previously dissolved in the melted ester compound (I) of from 60° to 150° C. and poured into water of from 60° to 100° C.; and the resulting mixture is emulsified or dispersed at a temperature of from 60° to 100° C. by means of a high-speed agitation emulsifying device at a rate of from 500 to 10000 rpm or a piston-type high-pressure emulsifying device at a pressure of from 50 to 500 kg/cm2 and then cooled. The ester compound (I) can be synthesized by the conventional methods. For example, a fatty acid or its acid halide and a monohydric aliphatic alcohol in a former to latter molar ratio of, generally, 1 to 1, or a fatty acid anhydride and a monohydric aliphatic alcohol in a former to latter molar ratio of, generally, 1 to 2 are subjected to dehydration or dehydrohalogenation at a temperature of from 70° to 200° C. in a nitrogen atmosphere until a required percent esterification is reached. For promoting esterification, catalysts such as hydrogen chloride, sulfuric acid, p-toluenesulfonic acid, boron trifluoride etherate, etc. may be used together. Dehydration or dehydrohalogenation may be carried out under reduced pressure, or dehydration may be carried out azeotropically using a solvent such as toluene, xylene, etc.
In using the lubricants for paper coating of the present invention, they may be mixed, in advance or in situ, with antioxidants, ultraviolet absorbers, water insolubilizers, antiseptic/anti-mould agents, insecticidal/fungicidal agents, dispersing agents, defoaming agents, deodorizing agents, perfumes, extenders, dyes, pigments, or other lubricants (e.g. calcium stearate, zinc stearate, potassium oleate, paraffin wax, polyethylene wax).
In using the lubricants for paper coating of the present invention, they are added to paper coating colors composed mainly of pigments and binders. The pigments include inorganic pigments such as clay, calcium carbonate, titanium dioxide, satin white, barium sulfate, talc, zinc oxide, etc., organic pigments such as plastic pigments (polystyrene described in Japanese patent Publication No. 6524/1971) and combinations thereof. The binders include natural binders, synthetic binders and mixtures thereof. The natural binders include starch, modified starch, soybean protein, casein, etc. The synthetic binders include styrene/butadiene latices; acrylic resin emulsions, particularly aqueous suspensions of polymers containing a small amount of a copolymerized ethylenically unsaturated carboxylic acid; butadiene/acrylonitrile copolymers, vinyl acetate/acrylate copolymers, butadiene/methyl methacrylate copolymers, vinyl chloride/vinylidene chloride copolymers, homopolymers comprising butadiene, methyl methacrylate, vinyl acetate, chloroprene, vinyl chloride and butyl methacrylate; and latices of polymeric materials which are at least partially soluble in aqueous media such as polyvinyl alcohol.
The amount calculated as solid of the lubricants for paper coating of the present invention is generally from 0.1 to 20 parts by weight, preferably from 0.2 to 10 parts by weight, more preferably from 0.3 to 5 parts by weight based on 100 parts by weight of the pigments. When the amount is less than 0.1 part by weight, any of the releasing effect, antidusting effect and print gloss improving effect is insufficient, and when it is larger than 20 parts by weight, the coated paper becomes too slippery, either of the both cases being not preferred.
The paper coating colors obtained with the lubricants for paper coating of the present invention are generally used in the form of aqueous dispersions. To the colors are added, as need arises, other additives such as dispersing agents (e.g. sodium pyrophosphate, sodium hexametaphosphate, sodium polyacrylate), defoaming agents (e.g. paraffin, phosphoric acid esters, polyglycol, silicone compounds), leveling agents (e.g. urea, dicyandiamide), water retention agents, flow modifiers (e.g. carboxymethyl cellulose, sodium alginate, hydroxyethyl cellulose), water insolubilizers (e.g. urea resins, melamine resins, glyoxal), antiseptic agents (e.g. formalin), fluorescent dyes, etc.
The paper coating colors of the present invention can be applied to base papers, for example, by means of air knife coaters, trailing blade coaters, inverted coaters, roll coaters, applicators, etc. After coating, the coated paper is dried and if necessary, finished by calendering or supercalendering. The coating temperature is generally from 10° to 60° C., the drying temperature is generally from 90° to 130° C., and the calendering temperature and supercalendering temperature are from 40° to 100° C.
The lubricants for paper coating of the present invention are very superior in the releasing effect and antidusting effect during calendering, and yet these effects are far superior to those of the conventional lubricants such as calcium stearate, etc. even at as low a dosage as from half to one-third of that of the conventional lubricants. Further, such a great reduction in the dosage made it possible to eliminate various adverse effects which cannot be avoided when the conventional lubricants are used at high dosage levels for the purpose of antidusting. Such adverse effects include efficiency reduction of paper rewinding and sheet feeding to a sheet-fed press owing to too much slip of paper, reduction in printability such as ink receptivity and wet strength of coated paper, reduction in glueability and blister pack property of coated white board, etc.
Also, the lubricants of the present invention have an effect to improve the print gloss of coated paper which has never been obtained with the conventional lubricants. Further, the lubricants, because of their antidusting effect, have also effects of improving the smoothness of coated paper, reducing missing dots in gravure printing and improving sheet gloss.
The lubricants for paper coating of the present invention can also be used as a sizing agent. The dosage can be varied, but it is generally from 0.01 to 5 wt. %, preferably from 0.05 to 2 wt. %, more preferably from 0.1 to 1 wt. %, as converted to solid basis, based on pulp. Paper which is sizable with the present lubricants is not particularly limited, but covers a wide range of base papers as well as papers made in a wide pH range independently of treatment with paper strength resins. When the lubricants of the present invention are used as a sizing agent, it suffices to add the present sizing agent and a fixing agent to an aqueous dispersion containing beaten pulp and a filler such as clay, calcium carbonate, etc. and after mixing, to make paper from the dispersion.
The lubricants of the present invention can also be used as a water insolubilizer for cement, gypsum board, etc.
The present invention will be illustrated with reference to the following examples, but it is not limited to these examples.
EXAMPLES 1 to 11 Preparation of Lubricant A
To an emulsifying machine or disperser equipped with a piston-type high-pressure emulsifying device were added 1230 g of water, 45 g of an addition polymer of octylphenol with 13 moles of ethylene oxide, 140 g of an addition polymer of lauryl alcohol with 14 moles of ethylene oxide, 45 g of a monoester of myristic acid with polyethylene glycol comprising 70 moles of ethylene oxide, 8 g of sodium dodecylbenzenesulfonate and 12 g of a sodium naphthalenesulfonate/formaldehyde condensate of a condensation degree of 5, and the mixture was heated to 80° C. to turn it into uniform solution. To the solution was added with stirring 1000 g of an ester of 2-undecyltetradecyl alcohol with montanic acid previously heated to 120° C., and the mixed solution was emulsified on the piston-type high-pressure emulsifying device at a pressure of 300 kg/cm2 and then immediately cooled to 28° C. Thus, a white emulsion or dispersion having a concentration of 50% and a viscosity of 300 cps (measured at 25° C.; same applies in the examples which follow) was obtained and designated as "lubricant A".
Preparation of Lubricant B
To the same emulsifying machine or disperser as used in the preparation of the lubricant A were added 1190 g of water, 90 g of an addition polymer of stearyl alcohol with 7 moles of ethylene oxide, 80 g of an addition polymer of lauryl alcohol with 14 moles of ethylene oxide and 15 g of a sodium salt of dihexyl sulfosuccinate and 5 g of sodium laurylsulfonate, and the mixture was heated to 70° C. to turn it into uniform solution. To the solution was added with stirring 1000 g of behenyl behenate previously heated to 120° C., and the mixed solution was emulsified on the piston-type high-pressure emulsifying device at a pressure of 300 kg/cm2 and then immediately cooled to 28° C. Thus, an emulsion or dispersion having a concentration of 50% and a viscosity of 150 cps was obtained and designated as "lubricant B".
Preparation of Lubricant C
To the same emulsifying machine or disperser as used in the preparation of the lubricant A were added 1138 g of water, 85 g of an addition polymer of stearyl alcohol with 14 moles of ethylene oxide, 25 g of a monoester of lauric acid with polyethylene glycol comprising 18 moles of ethylene oxide, 20 g of an addition polymer of nonylphenol with 20 moles of ethylene oxide, 4 g of a sodium naphthalenesulfonate/formaldehyde condensate of an average condensation degree of 3 and 4 g of sodium dodecylbenzenesulfonate, and the mixture was heated to 80° C. to turn it into uniform solution. To the solution was added with stirring 1000 g of stearyl stearate previously heated to 120° C., and the mixed solution was emulsified on a piston-type high-pressure emulsifying device at a pressure of 250 kg/cm2 and then immediately cooled to 25° C. Thus, a white emulsion or dispersion having a concentration of 50% and a viscosity of 120 cps was obtained and designated as "lubricant C".
Preparation of Lubricant D
To a high-speed agitation apparatus were added 1000 g of oleyl oleate, 60 g of an addition polymer of lauryl alcohol with 14 moles of ethylene oxide, 25 g of an addition polymer of stearyl alcohol with 23 moles of ethylene oxide, 40 g of a monoester of stearic acid with polyethylene glycol comprising 45 moles of ethylene oxide, 25 g of a monoester of myristic acid with polyethylene glycol comprising 23 moles of ethylene oxide, 10 g of sodium petroleumsulfonate and 0.15 g of potassium hydroxide. The resulting mixture was uniformly mixed at a temperature of 80° C., stirred at a high speed of 3000 rpm while adding 1160 g of 80° C. water in portions and then cooled to 27° C. Thus, a pale yellowish white emulsion or dispersion having a concentration of 50% and a viscosity of 60 cps (at 25° C.) was obtained and designated as "lubricant D".
Preparation of Lubricants E to J
Lubricants E to J were obtained in the same condition as in the preparation of the lubricant C. Every lubricant has a concentration of 50%. A white emulsion or dispersion of lauryl stearate having a viscosity of 105 cps is lubricant E. A white emulsion or dispersion of lauryl 12-hydroxystearate having a viscosity of 230 cps is lubricant F. A white emulsion or dispersion of 2-ethylhexyl stearate having a viscosity of 90 cps is lubricant G. A white emulsion or dispersion of butyl stearate having a viscosity of 80 cps is lubricant H. A white emulsion or dispersion of 2-ethylhexyl laurate having a viscosity of 85 cps is lubricant 1. A white emulsion or dispersion of palmityl butyrate having a viscosity of 80 cps is lubricant J.
Preparation of Lubricant P
To an emulsifying machine or disperser equipped with a piston-type high-pressure emulsifying device were added 1500 g of water and 75 g of the ammonium salt of a copolymer of monobutyl maleate with styrene, and the resulting mixture was heated to 80° C. to turn it into uniform solution. After adding 1425 g of lauryl stearate previously heated to 90° C. to the solution with stirring, the mixed solution was emulsified on the piston-type high-pressure emulsifying device at a pressure of 300 kg/cm2 and then cooled to 30° C. Thus, a white emulsion or dispersion having a concentration of 50% and a viscosity of 60 cps was obtained and designated as "lubricant P".
COMPARATIVE EXAMPLES 12 to 17 Preparation of Lubricants K to M
Lubricants K to M were obtained in the same condition as in the preparation of the lubricant C. Every lubricant has a concentration of 50%. An emulsion or dispersion of methyl stearate having a viscosity of 210 cps is lubricant K. An emulsion or dispersion of lauryl acetate having a viscosity of 130 cps is lubricant L. An emulsion or dispersion of butyl caprylate having a viscosity of 75 cps is lubricant M.
Preparation of Lubricant N
To the same emulsifying machine or disperser as used in the preparation of the lubricant A were added 1130 g of water, 120 g of a addition polymer of nonylphenol with 9.5 moles of ethylene oxide and 10 g of a sodium naphthalenesulfonate/formaldehyde fondensate of an average condensation degree of 3, and the resulting mixture was heated to 70° C. to turn it into uniform solution. After adding 1000 g of ethylene glycol distearate previously heated to 120° C. to the solution with stirring, the mixed solution was emulsified at a high pressure of 300 kg/cm2 and then immediately cooled to 25° C. Thus, a pale yellowish white emulsion or dispersion having a concentration of 50% and a viscosity of 200 cps was obtained and designated as "lubricant N".
Preparation of Lubricant O
A commercially available 50% calcium stearate dispersion was designated as "lubricant O".
Preparation of Lubricant Q
An emulsion or dispersion of lauryl stearate was prepared in the same manner as in the preparation of the lubricant E except that anionic surfactants, i.e. a sodium napthalenesulfonate/formaldehyde condensate of a condensation degree of 3 and sodium dodecylbenzenesulfonate were not added. The emulsion obtained had an abnormally high viscosity of 15000 cps at a concentration of 50%, and solidified in only one day, so that it could not be put to practical use.
Coating colors were prepared using the lubricants A to J and P of the present invention and for comparison, coating colors containing the lubricants K to 0 and no lubricant (blank) were prepared. Coated papers for test were prepared by applying these coating colors and evaluated for the antidusting property during supercalendering and physical properties as coated paper. The results are shown in Tables 1 and 2. The antidusting property was evaluated on both gravure paper prepared with a coating color for gravure printing and offset paper prepared with a coating color for offset printing. The physical properties as coated paper were evaluated on the offset paper. The coating color for gravure printing is a dispersion for paper coating having a solid content of 62% and a pH of 9.0 and comprising 45 parts of No. 1 pre-dispersed clay (Ultra White 90; a product of EMC Co.), 55 parts of No. 2 pre-dispersed clay (HT clay; a product of EMC Co.), 0.2 part of sodium polyacrylate type dispersing agent (SN-Dispersant 5040; a product of San Nopco Ltd.), 0.3 part of sodium hydroxide, 0.3 part of carboxymethyl cellulose (Cellogen PR; a product of Daiichi Kogyo Seiyaku Co.), 8 parts of carboxyl-modified styrene/butadiene copolymeric latex (JSR 0628; a product of Nippon Synthetic Rubber Co.) and 0 to 1 part of the lubricant.
The coating color for offset printing is a dispersion for paper coating having a solid content of 62% and a pH of 9.0 and comprising 70 parts of No. 1 pre-dispersed clay (the same as above), 15 parts of precipitated calcium carbonate (Tamapal TP-222H; a product of Okutama Kogyo Co.), 15 parts of ground calcium carbonate (Escaron #1500; a product of Sankyo Seifun Kako Co.), 0.2 part of sodium polyacrylate type dispersing agent (the same as above), 5 parts of oxidized starch (MS-3800; a product of Nippon Shokuhin Kako Co.), 12 parts of carboxyl-modified styrene/butadiene copolymeric latex (JSR 0692; a product of Nippon Synthetic Rubber Co.) and 0 to 1 part of the lubricant.
All the amounts of the ingredients of the above coating colors are part by weight converted to solid basis.
These coating colors were coated by means of a helicoater onto wood containing paper of a basis weight of 65 g/m2 for gravure paper and onto wood free paper of the same basis weight for offset paper. The amount of the coating color applied was 12 g/m2 for gravure paper and 16 g/m2 for offset paper.
The antidusting property was evaluated as follows: The coated paper obtained was passed through a supercalender at a temperature of 70° C. and at a nip pressure of 150 kg/cm, and the state of generation of dusting on the surface of the chilled roll was evaluated with naked eyes and expressed by the 10-point evaluation method. In this evaluation method, 10 is the best and 1 is the poorest.
The coated paper for measuring the physical properties as coated paper was tested after supercalendering at a temperature of 50° C. and at a nip pressure of 80 kg/cm.
As is apparent from the results of Table 1 and Table 2, the lubricants for paper coating of the present invention exhibit at a low dosage level excellent antidusting effect as well as excellent effect to improve sheet gloss, particularly print gloss.
              TABLE 1                                                     
______________________________________                                    
Antidusting property                                                      
            Item                                                          
           Antidusting property                                           
           **(10-point evaluation method)                                 
           Paper                                                          
           Gravure paper                                                  
                       Offset paper                                       
           *Dosage of lubricant (%)                                       
Lubricant    1.5    1.0   0.5  0   1.0  0.6 0.3  0                        
______________________________________                                    
Example  A       9.5    9.0 8.5  --  9.8  9.5 9.0  --                     
         B       9.5    9.0 8.5  --  9.8  9.5 9.0  --                     
         C       9.5    9.0 8.5  --  9.8  9.5 9.0  --                     
         D       9.5    9.0 8.5  --  9.8  9.5 9.0  --                     
         E       9.5    9.0 8.5  --  9.5  9.3 8.8  --                     
         F       9.5    9.0 8.5  --  9.5  9.3 8.8  --                     
         G       9.0    8.5 7.5  --  9.5  9.2 8.5  --                     
         H       8.5    8.0 7.0  --  9.3  9.0 8.3  --                     
         I       8.5    7.5 6.5  --  9.0  8.5 8.0  --                     
         J       8.5    7.5 6.5  --  9.0  8.5 8.0  --                     
         P       9.5    9.0 8.5  --  9.5  9.3 8.8  --                     
Comparative                                                               
         K       6      5.5 4.5  --  7.5  6.5 6.0  --                     
example  L       5.5    5   4.0  --  6.5  6.0 5.0  --                     
         M       4.5    4.0 4.0  --  5.5  5.5 5.0  --                     
         N       6.5    5.5 4.5  --  7.0  6.5 6.0  --                     
         O       6      5.5 4.5  --  7.0  6.5 6.0  --                     
         Blank   --     --  --   3.5 --   --  --   5.0                    
______________________________________                                    
 *Expressed by wt. % based on the pigment in the coating color.           
 **10Point evaluation method: (best) 10-1 (Poorest)                       
                                  TABLE 2                                 
__________________________________________________________________________
Physical properties as coated paper                                       
               Physical properties as coated paper                        
Lubricant            Sheet                                                
                         Print        Wet ink                             
           Dosage                                                         
               Whiteness                                                  
                     gloss                                                
                         gloss                                            
                            Dry pick                                      
                                 Wet pick                                 
                                      receptivity                         
       Name                                                               
           (%) (%)   (%) (%)                                              
                            10-Point evaluation method                    
__________________________________________________________________________
Example                                                                   
       A   1   80.6  77.4                                                 
                         86.1                                             
                            9      8.5                                    
                                      7                                   
       B   1   80.5  77.3                                                 
                         86.1                                             
                            9      8.5                                    
                                      7                                   
       C   1   80.5  77.4                                                 
                         86.0                                             
                            9    8    7                                   
       D   1   80.5  77.3                                                 
                         85.9                                             
                            9    8    7                                   
       E   1   80.6  77.0                                                 
                         85.7                                             
                            9    8    7                                   
       F   1   80.5  77.2                                                 
                         86.5                                             
                            9    8      7.5                               
       G   1   80.5  76.9                                                 
                         85.5                                             
                            9    8    7                                   
       H   1   80.5  76.3                                                 
                         84.8                                             
                            9    8    7                                   
       I   1   80.5  76.2                                                 
                         84.2                                             
                            9    8    7                                   
       J   1   80.5  76.0                                                 
                         83.9                                             
                            9    8    7                                   
       P   1   80.5  77.1                                                 
                         85.6                                             
                            9    8    7                                   
Comparative                                                               
       K   1   80.5  75.6                                                 
                         82.6                                             
                            9    8    7                                   
example                                                                   
       L   1   80.5  75.4                                                 
                         82.4                                             
                            9    8    7                                   
       M   1   80.5  75.1                                                 
                         82.3                                             
                            9    8    7                                   
       N   1   80.4  75.0                                                 
                         82.3                                             
                            9    8    7                                   
       O   1   80.5  75.2                                                 
                         82.4                                             
                            9    8    7                                   
       Blank                                                              
           --  80.5  75.0                                                 
                         82.2                                             
                            9    8    7                                   
__________________________________________________________________________

Claims (6)

What is claimed is:
1. A lubricant for paper coating which comprises,
an aqueous dispersion of an ester compound repersented by the formula (I), ##STR3## wherein R represents an alkyl group having 11 to 21 carbon atoms or an alkyl group having a hydroxyl group and having 11 to 21 carbon atoms, and R' represents an alkyl group having 12 to 22 carbon atoms, and
an emulsifier or a dispersant is
wherein the emulsifier or the dispersant is 0.1 to 40 parts by weight based on 100 parts by weight of the ester of compound of formula (I).
2. A lubricant as claimed in claim 1 wherein said ester compound has been emulsified or dispersed with at least one nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ether, polyoxyethylene alkyl ester and polyoxyethylene alkylphenyl ether and at least one anoinic surfactant selected from the group consisting of sulfonate-type anionic surfactants and sulfate-type anionic surfactants.
3. A lubricant as claimed in claim 1 wherein said ester compound has been emulsified or dispersed with the salt of a copolymer of an α, β-unsaturated dibasic acid or its monoester with styrene.
4. A method for producing a lubricant for paper coating comprising an aqueous dispersion characterized by
dispersing an ester compound represented by the general formula, ##STR4## wherein R represents an alkyl group having 11 to 21 carbon atoms or an alkyl group having a hydroxyl group and having 11 to 21 carbon atoms, and R' represents an alkyl group having 12 to 22 carbon atoms, by means of a high-speed agitation emulsifying device or piston-type high-pressure emulsifying device in the presence of water and a nonionic and aionic surfactants or the salt of a copolymer of an α, β-unsaturated dibasic acid or its monoester with styrene.
5. A coated paper comprising a paper substrate and coated thereon a coating composition comprising the lubricant of claim 1 and a pigment wherein the amount of lubricant in the coating composition is 0.1 to 20 parts by weight calculated as solids, based on 100 parts by weight of the pigment.
6. A coated paper comprising a paper substrate and coated thereon a coating composition comprising the lubricant of claim 2 and a pigment, wherein the amount, calculated as solids, of the lubricant in the coating composition is 0.1 to 20 parts by weight based on 100 parts by weight of the pigment.
US06/932,252 1985-11-20 1986-11-19 Lubricant for use in paper coating and method for producing the same Expired - Lifetime US4776970A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP60262132A JPS62104829A (en) 1985-01-22 1985-11-20 Production of polyurethane
JP60262131A JPH0660477B2 (en) 1985-11-20 1985-11-20 Lubricant for paper coating and manufacturing method thereof
JP60-262132 1985-11-20

Publications (1)

Publication Number Publication Date
US4776970A true US4776970A (en) 1988-10-11

Family

ID=26545408

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/932,252 Expired - Lifetime US4776970A (en) 1985-11-20 1986-11-19 Lubricant for use in paper coating and method for producing the same

Country Status (1)

Country Link
US (1) US4776970A (en)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5283129A (en) * 1992-10-21 1994-02-01 Champion International Corporation Light weight paper stock
DE19616733A1 (en) * 1996-04-26 1997-11-06 Stockhausen Chem Fab Gmbh Process for the thermal-mechanical surface treatment of sheet-like material webs, in particular of paper and cardboard, and means for carrying out the process
US6153040A (en) * 1998-05-15 2000-11-28 United States Gypsum Company Gypsum board paper that reduces roll up during lamination, and board comprising such paper
US6489040B1 (en) 2000-02-15 2002-12-03 United States Gypsium Company Wallboard with improved roll-up resistance
US6500790B1 (en) * 2001-06-08 2002-12-31 General Electric Company Magnetic wire external lubricant
US6776995B1 (en) 2002-05-28 2004-08-17 Rina Revivo Souffle facial and body scrub
US20060004137A1 (en) * 2002-05-23 2006-01-05 Douglas Shepherd Coating composition
US7101578B1 (en) 2004-03-01 2006-09-05 Spa De Soleil, Inc. Salt sorbet facial and body scrub
US20120208730A1 (en) * 2011-02-15 2012-08-16 Robert Chaffee Richmond Friction and Wear Modifiers Using Solvent Partitioning of Hydrophilic Surface-Interactive Chemicals Contained in Boundary Layer-Targeted Emulsions
CN108368446A (en) * 2015-12-10 2018-08-03 艺康美国股份有限公司 Abrasion masked composition and its application method for reusable container
CN113201964A (en) * 2021-05-10 2021-08-03 华东理工大学 Preparation method of papermaking lubricant

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3252907A (en) * 1962-03-23 1966-05-24 United States Steel Corp Method of making sheet steel and lubricant-protective composition useful therein
US3364143A (en) * 1962-03-07 1968-01-16 Swift & Co Method for improving the working properties of metals
US3505844A (en) * 1966-08-22 1970-04-14 Reynolds Metals Co Rolling lubrication
US3507792A (en) * 1967-11-30 1970-04-21 Sinclair Research Inc Biodegradable,water-dispersible lubricant compositions
US3657123A (en) * 1970-03-23 1972-04-18 Atlantic Richfield Co Lubricant compositions
US3857865A (en) * 1973-08-01 1974-12-31 Emery Industries Inc Ester lubricants suitable for use in aqueous systems
US3912642A (en) * 1973-08-01 1975-10-14 Emery Industries Inc Ester lubricants suitable for use in aqueous systems
US3945930A (en) * 1973-09-29 1976-03-23 Toho Chemical Industry Co., Ltd. Water-soluble metal working lubricants
US4137046A (en) * 1975-10-07 1979-01-30 Mitsubishi Paper Mills, Ltd. Transparent cellulosic paper and method for making the same
US4659489A (en) * 1984-06-22 1987-04-21 Diamond Shamrock Chemicals Company Lubricant dispersions for paper coating compositions
US4676836A (en) * 1984-10-16 1987-06-30 Diamond Shamrock Chemicals Company Anionic Lubricant dispersions useful in paper coatings

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3364143A (en) * 1962-03-07 1968-01-16 Swift & Co Method for improving the working properties of metals
US3252907A (en) * 1962-03-23 1966-05-24 United States Steel Corp Method of making sheet steel and lubricant-protective composition useful therein
US3505844A (en) * 1966-08-22 1970-04-14 Reynolds Metals Co Rolling lubrication
US3507792A (en) * 1967-11-30 1970-04-21 Sinclair Research Inc Biodegradable,water-dispersible lubricant compositions
US3657123A (en) * 1970-03-23 1972-04-18 Atlantic Richfield Co Lubricant compositions
US3857865A (en) * 1973-08-01 1974-12-31 Emery Industries Inc Ester lubricants suitable for use in aqueous systems
US3893931A (en) * 1973-08-01 1975-07-08 Emery Industries Inc Ester lubricants suitable for use in aqueous systems
US3912642A (en) * 1973-08-01 1975-10-14 Emery Industries Inc Ester lubricants suitable for use in aqueous systems
US3945930A (en) * 1973-09-29 1976-03-23 Toho Chemical Industry Co., Ltd. Water-soluble metal working lubricants
US4137046A (en) * 1975-10-07 1979-01-30 Mitsubishi Paper Mills, Ltd. Transparent cellulosic paper and method for making the same
US4659489A (en) * 1984-06-22 1987-04-21 Diamond Shamrock Chemicals Company Lubricant dispersions for paper coating compositions
US4676836A (en) * 1984-10-16 1987-06-30 Diamond Shamrock Chemicals Company Anionic Lubricant dispersions useful in paper coatings

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5283129A (en) * 1992-10-21 1994-02-01 Champion International Corporation Light weight paper stock
DE19616733A1 (en) * 1996-04-26 1997-11-06 Stockhausen Chem Fab Gmbh Process for the thermal-mechanical surface treatment of sheet-like material webs, in particular of paper and cardboard, and means for carrying out the process
DE19616733C2 (en) * 1996-04-26 2000-07-13 Stockhausen Chem Fab Gmbh Process for the thermal-mechanical surface treatment of sheet-like material webs, in particular made of paper and cardboard, using adhesive agents
US6156387A (en) * 1996-04-26 2000-12-05 Stockhausen Gmbh & Co. Kg Process for surface treatment of material webs, in particular paper and cardboard webs, using adhesive agents
US6153040A (en) * 1998-05-15 2000-11-28 United States Gypsum Company Gypsum board paper that reduces roll up during lamination, and board comprising such paper
US6489040B1 (en) 2000-02-15 2002-12-03 United States Gypsium Company Wallboard with improved roll-up resistance
US6500790B1 (en) * 2001-06-08 2002-12-31 General Electric Company Magnetic wire external lubricant
US20060004137A1 (en) * 2002-05-23 2006-01-05 Douglas Shepherd Coating composition
US6776995B1 (en) 2002-05-28 2004-08-17 Rina Revivo Souffle facial and body scrub
US7101578B1 (en) 2004-03-01 2006-09-05 Spa De Soleil, Inc. Salt sorbet facial and body scrub
US20120208730A1 (en) * 2011-02-15 2012-08-16 Robert Chaffee Richmond Friction and Wear Modifiers Using Solvent Partitioning of Hydrophilic Surface-Interactive Chemicals Contained in Boundary Layer-Targeted Emulsions
US8420582B2 (en) * 2011-02-15 2013-04-16 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Friction and wear modifiers using solvent partitioning of hydrophilic surface-interactive chemicals contained in boundary layer-targeted emulsions
CN108368446A (en) * 2015-12-10 2018-08-03 艺康美国股份有限公司 Abrasion masked composition and its application method for reusable container
CN108368446B (en) * 2015-12-10 2021-05-07 艺康美国股份有限公司 Wear masking composition for reusable containers and method of use
CN113201964A (en) * 2021-05-10 2021-08-03 华东理工大学 Preparation method of papermaking lubricant

Similar Documents

Publication Publication Date Title
US4776970A (en) Lubricant for use in paper coating and method for producing the same
US6123760A (en) Compositions and methods for preparing dispersions and methods for using the dispersions
DE60011450T2 (en) SURFACE FINISHING OF PAPER OR CARDBOARD AND MEDIUM FOR IT
KR100315879B1 (en) Fluorescent Bleaching Method of Paper
US4157995A (en) Paper coating composition containing a pigment, a polymer in the form of an aqueous dispersion and another polymer which is soluble in water
US4302367A (en) Paper-coating compositions
US5013775A (en) Sizing composition and sizing method
US6297317B1 (en) Water-retaining and optical-brightner-activating polymer composition, paper coating colors and sheets of coated paper thus obtained
US4659489A (en) Lubricant dispersions for paper coating compositions
US7732388B2 (en) Phospholipid lubricant for coating moving webs
US5527383A (en) Lubricant additives for paper coating compositions
PL81385B1 (en) Aqueous polymer dispersion method of producing same and their use as binders in paper coatings[us3746671a]
JPS62125095A (en) Paper coating lubricant and its production
AU2241199A (en) Paper sizing
GB2310215A (en) Coating composition
US3664987A (en) Functional sufrace coating compositions for cellulosic material
JP4142148B2 (en) Paper processing composition
JP2974729B2 (en) Lubricant for pigment coated paper
US3706590A (en) Functional surface coating compositions for cellulosic material
EP0502141A4 (en) Printable paper coating composition
JP3221188B2 (en) Rosin emulsion composition, method for producing the same, sizing agent, sizing method, and sized paper
JPH10212695A (en) Paper-sizing composition
GB1601641A (en) Aqueous paper coating compotion
JPH1143894A (en) Sizing agent composition for paper
JP2001303482A (en) Latex for paper coating

Legal Events

Date Code Title Description
AS Assignment

Owner name: SAN NOPCO LIMITED, 11, ICHINOHASHI NOMOTOCHO, HIGA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:HAYASHI, YOSHIHIRO;OKUBO, TAKESHI;TAKESHITA, KAZUHIRO;AND OTHERS;REEL/FRAME:004632/0786

Effective date: 19861024

Owner name: SAN NOPCO LIMITED,JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HAYASHI, YOSHIHIRO;OKUBO, TAKESHI;TAKESHITA, KAZUHIRO;AND OTHERS;REEL/FRAME:004632/0786

Effective date: 19861024

STCF Information on status: patent grant

Free format text: PATENTED CASE

CC Certificate of correction
FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12